Journal of Geodetic Science最新文献_第5页

Positional uncertainty of network RTK observations in a modern datum 现代基准下网络RTK观测的位置不确定性

IF 1.3

Journal of Geodetic Science Pub Date : 2021-01-01 DOI: 10.1515/jogs-2020-0116

T. Bernstein, V. Janssen

{"title":"Positional uncertainty of network RTK observations in a modern datum","authors":"T. Bernstein, V. Janssen","doi":"10.1515/jogs-2020-0116","DOIUrl":"https://doi.org/10.1515/jogs-2020-0116","url":null,"abstract":"Abstract The Geocentric Datum of Australia 2020 (GDA2020) is Australia’s new and much improved national datum. It is based on a single, nationwide least squares network adjustment that rigorously propagates uncertainty. This paper explores three options to include Network Real-Time Kinematic (NRTK) observations and their Positional Uncertainty (PU) in the survey control network of New South Wales (NSW) via the GDA2020 state adjustment. In the first option, PU is empirically estimated based on a dataset of more than 1,500 observations to obtain values that can be uniformly applied to all NRTK observations. In the second option, PU is calculated for each NRTK observation, based on the coordinate quality indicators provided by the Global Navigation Satellite System (GNSS) equipment. Both options continue to treat NRTK observations as point-based position solutions, resulting in poor correlation with surrounding survey control marks. The third option overcomes this issue by utilising the automatically computed GNSS baselines between NRTK observations and their Virtual Reference Station (VRS) to create a connected network that can be adjusted like a static GNSS network. Using a typical urban NRTK survey in Sydney as an example, it is shown that this method offers a rigorous computation of PU, while maintaining the quick and easy nature of NRTK positioning.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":"11 1","pages":"38 - 47"},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75188460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Analytical and numerical methods of converting Cartesian to ellipsoidal coordinates 将笛卡尔坐标转换为椭球坐标的解析和数值方法

IF 1.3

Journal of Geodetic Science Pub Date : 2021-01-01 DOI: 10.1515/jogs-2020-0126

G. Panou, R. Korakitis

引用次数: 4

Performance of a solution of the direct geodetic problem by Taylor series of Cartesian coordinates 用笛卡尔坐标的泰勒级数求解直接大地测量问题的表现

IF 1.3

Journal of Geodetic Science Pub Date : 2021-01-01 DOI: 10.1515/jogs-2020-0127

C. Marx

{"title":"Performance of a solution of the direct geodetic problem by Taylor series of Cartesian coordinates","authors":"C. Marx","doi":"10.1515/jogs-2020-0127","DOIUrl":"https://doi.org/10.1515/jogs-2020-0127","url":null,"abstract":"Abstract The direct geodetic problem is regarded on the biaxial and triaxial ellipsoid. A known solution method suitable for low eccentricities, which uses differential equations in Cartesian coordinates and Taylor series expansions of these coordinates, is advanced in view of its practical application. According to previous works, this approach has the advantages that no singularities occur in the determination of the coordinates, its mathematical formulation is simple and it is not computationally intensive. The formulas of the solution method are simplified in the present contribution. A test of this method using an extensive test data set on a biaxial earth ellipsoid shows its accuracy and practicability for distances of any length. Based on the convergence behavior of the series of the test data set, a truncation criterion for the series expansions is compiled taking into account accuracy requirements of the coordinates. Furthermore, a procedure is shown which controls the truncation of the series expansions by accuracy requirements of the direction to be determined in the direct problem. The conducted tests demonstrate the correct functioning of the methods for the series truncation. However, the considered solution method turns out to be significantly slower than another current method for biaxial ellipsoids, which makes it more relevant for triaxial ellipsoids.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":"37 1","pages":"122 - 130"},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81415416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Year by year closure adjustment of global mean sea level budget, inclusive of lumped snow, water vapor, and permafrost mass components 全球平均海平面收支的逐年关闭调整，包括集总雪、水汽和永久冻土质量分量

IF 1.3

Journal of Geodetic Science Pub Date : 2020-01-01 DOI: 10.1515/jogs-2020-0109

H. Iz, C. K. Shum

引用次数: 2

Testing normality of chosen R-estimates used in deformation analysis 检验变形分析中所选r估计的正态性

IF 1.3

Journal of Geodetic Science Pub Date : 2020-01-01 DOI: 10.1515/jogs-2020-0002

R. Duchnowski, P. Wyszkowska

{"title":"Testing normality of chosen R-estimates used in deformation analysis","authors":"R. Duchnowski, P. Wyszkowska","doi":"10.1515/jogs-2020-0002","DOIUrl":"https://doi.org/10.1515/jogs-2020-0002","url":null,"abstract":"Abstract The normal distribution is one of the most important distribution in statistics. In the context of geodetic observation analyses, such importance follows Hagen’s hypothesis of elementary errors; however, some papers point to some leptokurtic tendencies in geodetic observation sets. In the case of linear estimators, the normality is guaranteed by normality of the independent observations. The situation is more complex if estimates and/or the functional model are not linear. Then the normality of such estimates can be tested theoretically or empirically by applying one of goodness-of-fit tests. This paper focuses on testing normality of selected variants of the Hodges-Lehmann estimators (HLE). Under some general assumptions the simplest HLEs have asymptotical normality. However, this does not apply to the Hodges-Lehmann weighted estimators (HLWE), which are more applicable in deformation analysis. Thus, the paper presents tests for normality of HLEs and HLWEs. The analyses, which are based on Monte Carlo method and the Jarque–Bera test, prove normality of HLEs. HLWEs do not follow the normal distribution when the functional model is not linear, and the accuracy of observation is relatively low. However, this fact seems not important from the practical point of view.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":"12 1","pages":"7 - 13"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79909834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

On the BIC for determining the number of control points in B-spline surface approximation in case of correlated observations 在相关观测值的情况下，确定b样条曲面近似控制点数目的BIC

IF 1.3

Journal of Geodetic Science Pub Date : 2020-01-01 DOI: 10.1515/jogs-2020-0110

G. Kermarrec, H. Alkhatib

{"title":"On the BIC for determining the number of control points in B-spline surface approximation in case of correlated observations","authors":"G. Kermarrec, H. Alkhatib","doi":"10.1515/jogs-2020-0110","DOIUrl":"https://doi.org/10.1515/jogs-2020-0110","url":null,"abstract":"Abstract B-spline curves are a linear combination of control points (CP) and B-spline basis functions. They satisfy the strong convex hull property and have a fine and local shape control as changing one CP affects the curve locally, whereas the total number of CP has a more general effect on the control polygon of the spline. Information criteria (IC), such as Akaike IC (AIC) and Bayesian IC (BIC), provide a way to determine an optimal number of CP so that the B-spline approximation fits optimally in a least-squares (LS) sense with scattered and noisy observations. These criteria are based on the log-likelihood of the models and assume often that the error term is independent and identically distributed. This assumption is strong and accounts neither for heteroscedasticity nor for correlations. Thus, such effects have to be considered to avoid under-or overfitting of the observations in the LS adjustment, i.e. bad approximation or noise approximation, respectively. In this contribution, we introduce generalized versions of the BIC derived using the concept of quasi- likelihood estimator (QLE). Our own extensions of the generalized BIC criteria account (i) explicitly for model misspecifications and complexity (ii) and additionally for the correlations of the residuals. To that aim, the correlation model of the residuals is assumed to correspond to a first order autoregressive process AR(1). We apply our general derivations to the specific case of B-spline approximations of curves and surfaces, and couple the information given by the different IC together. Consecutively, a didactical yet simple procedure to interpret the results given by the IC is provided in order to identify an optimal number of parameters to estimate in case of correlated observations. A concrete case study using observations from a bridge scanned with a Terrestrial Laser Scanner (TLS) highlights the proposed procedure.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":"22 1","pages":"110 - 123"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80869024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Classification of poplar trees with object-based ensemble learning algorithms using Sentinel-2A imagery 基于Sentinel-2A图像的基于对象的集成学习算法的杨树分类

IF 1.3

Journal of Geodetic Science Pub Date : 2020-01-01 DOI: 10.1515/jogs-2020-0003

H. Tonbul, I. Colkesen, T. Kavzoglu

{"title":"Classification of poplar trees with object-based ensemble learning algorithms using Sentinel-2A imagery","authors":"H. Tonbul, I. Colkesen, T. Kavzoglu","doi":"10.1515/jogs-2020-0003","DOIUrl":"https://doi.org/10.1515/jogs-2020-0003","url":null,"abstract":"Abstract The poplar species in the forest ecosystems are one of the most valuable and beneficial species for the society and environment. Conventional methods require high cost, time and labor need, and the results obtained vary and are insu˚cient in terms of achieved accuracy level. Determination of poplar cultivated fields and mapping of their spatial sites play a vital role for decision-makers and planners to enhance the economic and ecological value of poplar trees. The study aims to map Poplar (P. deltoides) cultivated areas in Akyazi district of Sakarya, Turkey province using various combinations of the Sentinel-2A image bands. For this purpose, object-based classification based on multi-resolution segmentation algorithm was utilized to produce image objects and ensemble learning algorithms, namely, Adaboost (AdaB), Random Forest (RF), Rotation Forest (RotFor) and Canonical correlation forest (CCF) were applied to produce thematic maps. In order to analyze the effects of the spectral bands of the Sentinel-2A image on the object-based classification performance, three datasets consisting of different spectral band combinations (i.e. four 10 m bands, six 20 m bands and ten 10m pan-sharpened bands) were used. The results showed that the RotFor and CCF classifiers produced superior classification performances compared to the AdaB and RF classifiers for the band combinations regarded in this study. Moreover, it was found that determination of poplar tree class level accuracy reached to ~94% in terms of F-score. It was also observed that the inclusion of the six spectral bands at 20 m resolution resulted in a noteworthy increase in classification accuracy (up to 6%) compared to single 10m band combination.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":"19 1","pages":"14 - 22"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81585850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Conflation of satellite altimetry and tide gauge records at coast 海岸卫星测高和潮汐计记录的合并

IF 1.3

Journal of Geodetic Science Pub Date : 2020-01-01 DOI: 10.1515/jogs-2020-0113

H. Iz, C. Shum, T. Y. Yang

引用次数: 5

A statistical protocol for a holistic adjustment of global sea level budget 全球海平面预算整体调整的统计议定书

IF 1.3

Journal of Geodetic Science Pub Date : 2020-01-01 DOI: 10.1515/jogs-2020-0001

H. Iz, C. Shum

{"title":"A statistical protocol for a holistic adjustment of global sea level budget","authors":"H. Iz, C. Shum","doi":"10.1515/jogs-2020-0001","DOIUrl":"https://doi.org/10.1515/jogs-2020-0001","url":null,"abstract":"Abstract Current studies in global mean sea level, GMSL, studies assess the closure/misclosure of the GMSL budget components and their uncertainties. Because Earth’s hydrosphere conserves water, a closed global mean sea level budget with a consistent set of estimates and their statistics is necessary. An unclosed budget means that there are problems to be addressed such as biases in the budget components, unreliable error statistics about the estimates, unknown or known but unmodeled budget components. In a misclosed global mean sea level budget, as practiced in recent studies, the trend estimates for the budget components and their errors account only for the anomalies of each budget component in isolation. On the other hand, the trend of each series must consider the trends of the other series in tandem such that the global mean sea level budget is closed for a holistic assessment, which can only be achieved by adjusting global mean sea level budget components simultaneously. In this study, we demonstrate a statistical protocol to ameliorate this deficiency, which potentially have implications for future sea level science studies, including the future Intergovernmental Panel on Climate Change (IPCC) Assessment Reports, and the US Climate Assessment Reports.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":"2 1","pages":"1 - 6"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88843452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Semi-kinematic geodetic reference frame based on the ITRF2014 for Malaysia 基于ITRF2014的马来西亚半运动学大地测量参考系

IF 1.3

Journal of Geodetic Science Pub Date : 2020-01-01 DOI: 10.1515/jogs-2020-0108

M. Azhari, Z. Altamimi, G. Azman, M. Kadir, W. Simons, R. Sohaime, M. Yunus, M. Irwan, C.A. Asyran, N. Soeb, A. Fahmi, A. Saiful

{"title":"Semi-kinematic geodetic reference frame based on the ITRF2014 for Malaysia","authors":"M. Azhari, Z. Altamimi, G. Azman, M. Kadir, W. Simons, R. Sohaime, M. Yunus, M. Irwan, C.A. Asyran, N. Soeb, A. Fahmi, A. Saiful","doi":"10.1515/jogs-2020-0108","DOIUrl":"https://doi.org/10.1515/jogs-2020-0108","url":null,"abstract":"Abstract Malaysia is located at the stable part of the tec-tonic Sundaland platelet in SE Asia. The platelet is surrounded in almost every direction by tectonically active convergent boundaries, at which the Philippine Sea, the Australian and the Indian Plates are subducting respectively from the East, South and West.The current Malaysia geodetic reference frame called MGRF2000 is a static reference frame and hence did not incorporate the effects of plate motion and the ensuing deformation from (megath-rust) earthquakes. To prevent degradation of Continuously Operating Reference Station (CORS) coordinates, a new time-dependent national reference frame was developed. Taking advantage of the availability of the GNSS data of the CORS network in Malaysia, notably the Malaysia Active GPS System (MASS) and Malaysia Real-Time Kinematic GNSS Network (MyRTKnet), a more accurate and robust Malaysian geodetic reference frame was determined, fully aligned and compatible with ITRF2014. The cumulative solution obtained from stacking Malaysian CORS position time series formed the basis of the new MGRF2020 realization. It consists of 100+ station positions at epoch 2020.0, station velocities and Post-Seismic Deformation (PSD) parametric models for stations subjected to major earthquakes. The (1999-2018) position time series exhibit Weighted Mean Root Square (WRMS) values of 3.0, 3.2 and 7.6 mm in respectively the East, North and Vertical components. A new semi-kinematic geodetic datum (GDM2020) for Malaysia, useable for GIS, mapping and cadastre applications is proposed to replace the existing static datum (GDM2000). A transformation suite to convert the spatial databases from GDM2000 to GDM2020 was also developed.","PeriodicalId":44569,"journal":{"name":"Journal of Geodetic Science","volume":"9 1","pages":"91 - 109"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84218192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3